[Mesa-dev] [PATCH 4/5] r600g, radeonsi: Use write-combined persistent GTT mappings

Marek Olšák maraeo at gmail.com
Wed Jul 23 04:52:17 PDT 2014

This sounds good to me.


On Wed, Jul 23, 2014 at 8:32 AM, Michel Dänzer <michel at daenzer.net> wrote:
> On 18.07.2014 20:45, Marek Olšák wrote:
>> If the requirements of GL_MAP_COHERENT_BIT are satisfied, then the
>> patch is okay.
> AFAICT GL_MAP_COHERENT_BIT simply means the app doesn't need to call
> glMemoryBarrier() to ensure coherency between access to the mapping and
> GL commands. Since we don't need to do anything for glMemoryBarrier(),
> GL_MAP_COHERENT_BIT doesn't make any difference for us.
> That said, I think I need to add code in the kernel ensuring we always
> flush the HDP cache before submitting a command stream to the hardware,
> bump the minor version, and only use VRAM for streaming when the DRM
> minor version is >= the bumped version.
> --
> Earthling Michel Dänzer            |                  http://www.amd.com
> Libre software enthusiast          |                Mesa and X developer

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